Gale Warning 1, NWS San Diego, CA

Area Forecast Discussion
National Weather Service San Diego CA
900 AM PDT Sun Apr 10 2022

.SYNOPSIS...
The cooling trend will continue through Tuesday as a trough of low
pressure deepens over the western United States. Night and morning
low clouds with partial afternoon clearing will prevail through
Monday night. Strong gusty west winds will occur Monday afternoon
through Tuesday morning, especially in the mountains, deserts and
coastal waters, and there is also a chance of light precipitation
Monday night from the mountains west to the coast. Slight warming
will occur around mid-week but another trough of low pressure could
bring more cooling and windy conditions late this week.

&&

DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

-Forecast Highlights-

* Cooling trend continues through Tuesday
* Strong gusty west winds Monday PM-Tuesday AM
* Light rain possible Monday night, especially coastal slopes

Low clouds covered many areas west of the mountains, which will
generally clear slowly today due to two layers of clouds and a
coastal eddy, and some locations near the coast may not clear
entirely this afternoon. The NKX sounding this morning had up to 15
deg C cooling between 900 and 950 MB, and this will combine with the
low clouds and coastal eddy to bring substantial cooling today.
Onshore MSLP gradients have relaxed somewhat from the values of last
night (only 5.6 MB SAN-IPL) but should increase again this
afternoon, contributing to the moderately strong gusty winds again
in the mountains and deserts, with some gusts over 45 MPH late this
afternoon and tonight.

Broad moderate-amplitude troughing prevails over the western US, and
that will continue through Monday when a wave moves from the Pacific
NW towards the Great Basin. We will catch the south end of that wave
with strong north-south height gradients aloft and strong surface
MSLP gradients to bring strong winds to the region, especially the
mountains and deserts Monday afternoon through early Tuesday
morning. A cold front should move through Monday night and should
enhance the winds over the coastal waters as well where gale force
winds could occur. Any precipitation that occurs will likely be near
the cold front and minimal, mostly less than 1/10" as most of the
moisture will be restricted to below 850 MB. Little or no snow is
expected over the mountains as most of the snow level falls to below
4000 feet will occur after the moisture decreases, and the air mass
will mostly be dry where the temps aloft are below freezing. It will
be chilly Tuesday with temperatures 5-15 deg F below average, with
40s in most mountain areas and only the 70s in the lower deserts.

Dry conditions are expected starting Tuesday with little or no
marine layer at least initially. Zonal flow will occur over the
southwestern US as low pressure aloft covers most of the northern US
and southern Canada, and this will help temperatures recover some
but will likely stay a little below normal. Most model/ensemble
solutions show another trough digging south around Fri/Sat but with
limited moisture, so if any precipitation occurs, it would likely
only be a few hundredths of an inch. We could get another round of
strong gusty winds in the mountains/deserts/coastal waters with that
next low, not at all unusual for this time of year.

&&

.AVIATION...
101520Z...Coast/Valleys...BKN-OVC bases ranging from 1500-2500 ft
MSL and areas of vis 4-6 SM in BR/HZ continuing through 16-18Z for
most areas. Moderate confidence in coastal areas remaining BKN-OVC
through the afternoon, especially VCTY KSAN. Stratus will begin to
spread back inland after 11/00Z with bases near 2000 ft MSL and tops
near 2500 ft MSL.

Mountains/Deserts...Mostly clear with unrestricted vis through
Monday morning. Winds increase again after 11/00Z with surface gusts
25-35 kt, strong up/downdrafts, and areas of LLWS likely over/east
of the mountains, including near KPSP. Winds will weaken very
slightly starting around 09-12z Mon before increasing again later
Monday afternoon.

&&

.MARINE...
Northwest winds will increase Monday and Tuesday, with gale force
winds expected Monday afternoon through Tuesday morning. Gusts near
35 kts and combined seas of 8-12 feet are possible. A Gale Watch
remains in effect for the inner and outer waters from late Monday
afternoon through early Tuesday morning. Winds will continue to gust
20-30 kts for much of Tuesday, weakening Tuesday night.

&&

.BEACHES...
As northwest winds increase late Monday and Tuesday, shorter-period
NW wind swell of 10-12 ft at 8-10 seconds arrives at the beaches,
with surf heights potentially exceeding 6 ft at times late Monday
Night and early Tuesday morning. Surf will then gradually decrease
through late week.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...High Wind Watch from Monday morning through late Monday night
     for Apple and Lucerne Valleys-Riverside County Mountains-
     San Bernardino County Mountains-San Diego County Mountains-
     San Gorgonio Pass Near Banning.

PZ...Gale Watch from Monday afternoon through Tuesday morning for
     Coastal Waters from San Mateo Point to the Mexican Border
     and out to 30 nm-Waters from San Mateo point to the Mexican
     Border Extending 30 to 60 nm out including San Clemente
     Island.

&&

PUBLIC...Maxwell
AVIATION/MARINE...Adams